This invention relates to bulk boxes, and more specifically to a rotating sidewall stop adapted for supporting the folding sidewalls of a height-extended bulk box.
In general, bulk boxes are designed to function as a container in a wide variety of uses, including in manufacturing, assembly, shipping and storage applications, and have foldable sidewalls that permit such bulk boxes to be collapsed by folding down the sidewalls. This substantially reduces the volume occupied by empty boxes and greatly increases the number of empty boxes that can be shipped or stored in a defined space. This ability increases the value of the boxes by permitting them to be shipped in an empty, collapsed condition at substantially less cost back to a facility where the sidewalls are again raised into a locked, upright position and then refilled with contents to be shipped for use elsewhere.
Conventional bulk boxes include a base and four folding sidewalls attached to the base and movable between vertically upright and collapsed conditions. The base includes two opposing base walls that have a predetermined short height with the other set of opposing base walls being taller. On the top rim of the base walls are pivot-mounting elements that accept pivot elements on the bottom of the sidewalls, which both fix the sidewalls to the base walls and allow the sidewalls to rotate relative to the base walls between vertically upright and collapsed positions. The pair of sidewalls connected to the short base walls are of equivalent height to one another but are taller than those of the pair of sidewalls connected to the taller base walls, which are of equivalent height to one another. This difference in heights is established so that the top rims of the taller sidewalls and the top rims of the shorter sidewalls are at the same height when the box is erected and create a flat plane for stacking.
One pair of sidewalls is folded down first and then the other pair. The bulk boxes are usually designed so that the individual sidewalls of each pair can be folded down in a non-sequential order for the convenience of the user. Whichever of the two sidewalls is folded down first, usually folds down until it rests on the top deck of the base. The top deck of the base provides a stop to the rotation of the sidewall as well as structural support. The second sidewall of the pair is then folded down to set on top of the first sidewall. In a bulk box without a height-extended base, the base itself supports each of the four of the sidewalls, as they are sequentially rotated 90 or 90+ degrees from the upright position into the collapsed position against the base.
Some bulk boxes have bases with height-extending walls that extend upwardly from the base and to the tops of which the respective sidewalls are rotatably attached. Thus, in the height-extended bulk boxes, there are three sets of walls—four base walls, four upward-extending, height-extending walls and four pivoting sidewalls.
In such a height-extended bulk box, the four height-extending walls are attached to the base in a fixed, non-pivoting manner. The top architecture of these height-extending walls match the architecture of the base walls in that the top sidewall, pivot-mounting provisions are identical to those of the base walls and the height difference between the pairs of base walls are duplicated in the tops of the height-extending walls. This is done so that the folding sidewalls can attach to the tops of the height-extending walls in the identical fashion as they do on the base walls and so the sidewalls can also pivot and fold down in the same fashion on the height-extending walls as they do on the base walls.
However, there is a required difference in function dictated by this height-extended arrangement, because the sidewall pivots are now elevated to the height of the top edge of the height-extending walls. Whichever of the two sidewalls is folded down first cannot reach and thus be supported by the top deck of the base. Therefore, there is nothing to stop its rotation and nothing to provide structural support to it above the level of the base. It is possible that in height-extended bulk boxes, the rotation of this first folding wall will continue unimpeded and may pull the sidewall pivots out of the mounting provisions in the top of the height-extending walls or cause damage to the sidewall pivots. Some prior art sidewall stops are fixed in position on the height-extending walls and cannot be removed when not in use. This impinges on the usable internal volume of the erected, height-extended bulk box. Preventing the over-rotation of the sidewalls while avoiding the disadvantages of the prior art is a purpose of this invention.